Limpograss shows real potential as an alternative forage grass for North Florida, providing significant summer growth, and can be stockpiled for grazing through December. Photo credit: Yoana Newman
Jose Dubeux, Erick Santos, David Jaramillo, Liza Garcia, UF-IFAS NFREC
Limpograss (Hemarthria altissima) has been successfully adopted in South Florida by livestock producers. This unique grass grows well in flatwood soils, and maintains its digestibility for longer periods than other warm-season grasses (e.g. bahiagrass and bermudagrass), making it a good candidate for stockpiling. Limpograss is also less sensitive to day-length than other grasses, growing during the cool-season, especially in mild-winters in South Florida. After a frost, limpograss will be one of the first warm-season grasses to initiate regrowth. The first cultivars were released in Florida during the 1970s and 80s, and include the diploids “Redalta” and “Greenalta” and the tetraploids “Bigalta” and “Floralta” (Newman et al., 2014). Recently, two new cultivars were released, “Kenhy” and “Gibtuck.” These cultivars provide increased grazing tolerance, greater productivity, and nutritive value compared to previously released cultivars (Wallau et al., 2015). Limpograss is often used for stockpiling, considering its slower loss of digestibility compared to other warm-season grasses.
The potential of limpograss in North Florida, however, has not fully been assessed. Although limpograss collections have been established in North Florida since 2005, a comprehensive evaluation including biomass productivity and nutritive value of the new cultivars has not been evaluated. The persistence of limpograss throughout these years, however, shows the possibility to grow this species in North Florida, despite the cooler temperatures compared to South Florida.
Along the Florida Panhandle there are vast areas that can potentially be used with limpograss, especially along the Gulf coast. One of the concerns of growing limpograss in North Florida is the shorter growing season, as compared to South Florida, because of the earlier frost. Comprehensive evaluations are necessary in order to assess these potential differences of limpograss performance in contrasting Florida environments.
Researchers established a limpograss trial at the UF-IFAS North Florida Research and Education Center (NFREC) in Marianna, Florida. Plots were established in July 2014 and included four limpograss cultivars (breeding line 1 and the cultivars Kenhy, Floralta, and Gibtuck). For comparison, the trial also included Tifton-85 bermudagrass as a control. From May 2015 to Feb 2017, researchers evaluated biomass productivity and digestibility (IVOMD) of these different grasses. Harvesting started in May of each year, with 5-week intervals between harvests and 7 inches cutting height. From May to August, after each harvest, plots received 60 lb. N/acre, 15 lb. P2O5/acre, and 60 lb. K2O/acre. Starting in September, a stockpiling scenario was simulated by letting the plants grow and harvesting only a portion of each plot every 5 weeks. Forage harvest measurements were taken to evaluate the cumulative growth since August.
During the summer growth of 2016, forage growth peaked in July. Gibtuck was one of the most productive among the limpograss cultivars with comparable growth to Tifton-85 Bermudagrass, which is considered one of the most productive Bermudagrass cultivars available (Figure 1). Starting in September, plants accumulated biomass until December, showing their potential for use for stockpiling in North Florida. During the primary stockpiling period, Kenhy showed the greatest potential. After December, there was limited gain in biomass accumulation for most of the cultivars (Figure 1).
Figure 1. Herbage accumulation of limpograss germplasm and Tifton-85 bermudagrass from May 2015 to Jan 2016. UF-IFAS NFREC, Marianna, FL.
In the second year (May 2016 to Jan 2017), forages peaked earlier in the growing season and declined during the summer. This likely reflects the reduced rainfall combined with the frequent harvesting (5 weeks) compromising the productivity not only of the limpograss, but also of the Tifton-85 bermudagrass. During the stockpiling period, the grasses demonstrated a similar trend of biomass accumulation until December (Figure 2).
Figure 2. Herbage accumulation of limpograss germplasm and Tifton-85 bermudagrass from May 2016 to Jan 2017. UF-IFAS NFREC, Marianna, FL.
Digestibility (IVOMD) of limpograss was often greater than Tifton-85 bermudagrass, especially during the stockpiling period (Figure 3). Limpograss digestibility (IVOMD = 55-60%) was maintained through December 2016, when it was significantly reduced, due to colder temperatures and frosts. The growth and digestibility data indicate that limpograss can be used during the summer, and for stockpiling at least through December without significant loss in digestibility. This would be sufficient to fill the November-December forage gap that often occurs in the Panhandle, allowing time for the cool-season forage production to ramp up. As a result, stockpiled limpograss could be utilized to reduce hay requirements, and ultimately reduce winter feeding expenses.
Figure 3. In vitro organic matter digestibility (IVOMD) of limpograss germplasm and Tifton-85 bermudagrass from May 2015 to Feb 2016. UF-IFAS NFREC, Marianna, FL.
Take Home Message
The results of this two-year trial in Marianna are encouraging. Limpograss shows real potential as an alternative forage grass for North Florida. Limpograss provided significant summer growth, but adds the potential use for stockpiled grazing through December. In general, limpograss was more digestible than Tifton-85 bermudagrass, especially during the stockpiling period. Variations among limpograss cultivars occurred, but those differences were not consistent over the two years. Therefore, all the cultivars tested have potential for use in North Florida. Longer-term evaluation with animal performance is still needed to fully asses the potential of limpograss in North Florida, but the results from this trial show that further evaluation is warranted.
- Newman, Y.C., J. Vendramini, L.E. Sollenberger, and K. Quesenberry. 2014. Limpograss (Hemarthria altissima): overview and management. EDIS SS-AGR-320.
- Wallau, M.O., L.E. Sollenberger, J.M.B. Vendramini, M.K. Mullenix, K.H. Quesenberry, C.A.M. Gomide, V. Costa e Silva, and N. DiLorenzo. Herbage accumulation and nutritive value of limpograss breeding lines under stockpiling management. Crop Science 55:2377-2383.
Jose Dubeux and Liza Garcia, University of Florida – North Florida Research and Education Center
Figure 1. Honeybee on white clover at UF-IFAS Citra. Photo credit: Jose Dubeux
Improved forages are not only good for livestock, but they can also help feed bees! Managing grasslands to enhance bee habitat requires similar management practices to those needed to enhance pasture for grazing livestock. Diversification of pasture species, management to increase the flowering period, and proper grazing management (no overgrazing) are key practices to enhance habitat for bees (Figure 1), and other native insects that also provide plant pollination. These practices are also important to improve livestock performance and sustainability of grasslands.
Bees are the primary pollinators and they benefit 1/3 of the world’s crop-based production. Bee populations are declining, affecting plants that rely upon them. Reasons for bee decline are diverse, and include land-use change leading to loss and fragmentation of habitats, agriculture intensification, pesticide application and environmental pollution, decreased resource diversity, alien species, the spread of pathogens, and climate change.
Both livestock and bees benefits from forage legumes. Cattle perform better on grass-legume mixtures compared to grass monocultures, because of the greater digestibility and crude protein found in legumes when compared to grasses. Legumes also add nitrogen to pastures via biological N2-fixation (BNF), enhancing forage productivity, and ultimately, stocking rate and gain per area. Bees benefit from legumes because of the flowers they feed on (Figures 2 and 3). Bees do benefit from grass flowering as well, however, diversifying the forage species also improves bee diet, providing opportunities for selection and improved nutrition.
Figure 2. Bumblebee on Crimson clover at UF-IFAS NFREC in Marianna. Photo credit: Jose Dubeux
Figure 3. Bumblebee grazing on crimson and white clovers at UF-IFAS NFREC in Marianna. Photo credit: Liza Garcia.
At the UF-IFAS North Florida Research and Education Center in Marianna, researchers are assessing the bee population on grass monocultures and grass-legume mixtures, under grazing conditions. For the grass-legume system, they are evaluating a bahiagrass-perennial peanut mixture during the warm-season, overseeded with rye, oats, and a blend of crimson, red, and ball clovers in the cool-season. The grass monoculture system they are comparing is bahiagrass during the warm-season, overseeded with rye and oats during the cool-season. Over the last two years, they have been putting out traps for 24 hours and collecting bees every 28 days in these contrasting grazing systems (grass vs. grass-legume pastures). Thirteen bee species were already identified, including 11 native bee species. Native bees are extremely important, since they are generally better pollinators than honeybees. Wild native bees are mostly pollen collectors and help pollinate many of our agricultural crops, maintain productivity, and plant diversity. Adding forage legumes increased the flower density (flower number per unit area). As a result, some of the bee species occurred more frequently in the grass-legume system as compared to the grass monocultures (Figure 4).
Figure 4. Number of Melissodes communis per trap in grazed paddocks of grass monoculture and grass-legume mixtures.
Figure 5. Honeybee on perennial peanut flower. Photo Credit: Jose Dubeux.
Take home message
Bees and livestock might have more in common than you think! They both need a diverse forage diet, so adding forage legumes to the pasture benefits bees and livestock. Adding forage legumes extends the flowering period benefiting native bees. Legumes enhance cattle performance because of greater nutritive value. Enhancing bee habitat will also have a positive cascade effect on crop pollination over the long-term, enhancing crop productivity as a result. This win-win situation also benefits the environment. Cool-season forage crop planting time is here, so this is a good opportunity to integrate clovers into your grazing system. Perennial Peanut is the most productive warm-season perennial legume for Florida. Researchers at UF/IFAS are developing techniques to integrate perennial peanut into bahigrass pastures as well. The investment to add legumes into your grazing operation is worth making just for the improved animal performance, but it will also enhance the habitat for pollinators that are so important for the environment and our food systems.
More information related to this topic:
Jose Dubeux, Liza Garcia, David Jaramillo, Erick Santos, UF/IFAS North Florida Research and Education Center
You might not be familiar with the term “Ecosystem Services,” but putting it simply, these are the benefits obtained from ecosystems (interactions between living organisms in a particular environment). These services benefit both people and the environment. Ecosystem services (ES) provided by grasslands include not only products such as beef and milk (provisioning ES), but also biological nitrogen fixation (N2-fixation) and nutrient cycling (supporting ES), carbon sequestration and greenhouse gas mitigation, water capture and purification, shade, windbreaks, habitat for pollinators and wildlife (regulating ES), and finally cultural (e.g. habitat for wildlife), and aesthetic ES.
Grassland managers are providing all these benefits to society, and they ought to receive compensation for that. Payment mechanisms might work in various ways, including tax breaks, direct monetary compensation, and cost-share programs. The first step, however, is to quantify and assign a monetary value to these ES. Researchers at the University of Florida are trying to accomplish this through a USDA-funded project currently being conducted in Marianna and Gainesville, Florida.
Figure 1. Honeybee on white clover flower in Citra, FL (left) and on rhizoma peanut (perennial peanut) flower in Marianna, FL (right). Photo credit: Jose Dubeux
When legumes are integrated into grass pastures, the potential to provide additional ES is increased. Legumes are able to fix atmospheric-N2 by associating with soil bacteria (reducing N-fertilizer input as a result), provide flowers for pollinators (Figure 1 above), and improve forage quality. Preliminary data indicate that 12 different bee species benefit from grass-legume pastures in Marianna. Adding legumes might also increase primary productivity in low-input systems, with grass-legume mixtures outperforming monocultures, enhancing nutrient cycling and carbon sequestration.
Figure 2. Typical in vitro organic matter digestibility (IVOMD) and crude protein (CP) of bahiagrass and rhizoma peanut.
Forage legumes are often more digestible and have greater crude protein than grasses (Figure 2 above). This often results in greater livestock performance when grazing on grass-legume pastures as opposed to grass monocultures (Figure 3 below).
Figure 3. Livestock performance (average daily gain – ADG) on unfertilized Bahiagrass, N-fertilized Bahiagrass (100 lbs. N/acre), and Bahiagrass-rhizoma peanut pastures (Dubeux et al., 2016).
Currently researchers at North Florida Research and Education Center in Marianna are assessing the ES provided by N-fertilized grasses and grass-legume systems . Grass-legume systems of Bahiagrass-rhizoma peanut pastures in the summer are overseeded with cool-season grasses (rye and oat) and clovers (crimson, red, and ball) over the winter (Figure 4 below).
Figure 4. Grass-legume pastures in Marianna, FL. On the left, warm-season mixture with Argentine bahiagrass and Ecoturf rhizoma peanut; on the right, cool-season mixture with cool-season grasses and clovers. Photo credit: Jose Dubeux
Preliminary results indicate similar livestock gains for grass-legume systems fertilized only with only 30 lbs. of nitrogen per acre, compared to grass only systems fertilized with 200 lbs. N/acre (Table 1).
Other ecosystem services are currently being assessed in the same project. A multidisciplinary team is working on different aspects of grassland ecosystems, including soil, vegetation, livestock, bees, water quality, and economics. At the end of the project, the hope is to provide comprehensive information on all these aspects.
Take Home Message
Grasslands produce far more than beef and milk. They provide additional ecosystem services (ES) that benefit society. Integrating forage legumes into grasslands enhances the capacity to provide these benefits. In Marianna, researchers are assessing an array of ES provided by N-fertilized grass and also by grass-legume pastures. Preliminary results indicate the possibility to produce similar livestock gains in grass-legume pastures using only 15% of the N-fertilization typically used in grass monocultures. Other ES such as presence of bees, carbon sequestration, and mitigation of greenhouse gases are also being assessed. The goal is to quantify the economic value for these different ES provided by grazing systems. Public policies could then be established to provide financial incentives to livestock producers through conservation programs. Hopefully these incentives would at least offset some of the cost of establishment for grass-legume systems on farms. With ES benefits more clearly defined, this could become a win-win situation, both for society and for the land owner.
Dubeux, J.C.B., Jr., L. Garcia, N. DiLorenzo, C. Prevatt, A. Blount, C. Mackowiak, E. Santos, D. Jaramillo, M. Ruiz-Moreno. 2016. Reduce your N fertilizer cost and maintain cattle productivity by planting forage legumes. The Florida Cattlemen and Livestock Journal, December 2016, v.81, n.3, p.94-97.
Jose Dubeux, A. Blount, C. Mackowiak, E. Santos, D. Jaramillo, L. Garcia, J. Pereira Neto, L. Dantas
Things do not always happen according to plan, especially this fall for cool-season forage planting. The recommended planting period of cool-season grasses in North Florida ranges from October 15th to November 15th. However, this year North Florida suffered a severe drought during this planting window. Unless the producer had irrigation available, cool-season forage plantings were delayed. For many counties in North Florida, rainfall did not return until the last day of November. Many producers have asked if it was still worthwhile to plant cool-season grasses, or if it would be better just to buy hay and feed? There is not enough information available on late planting of cool-season forage yields, so people rely on past experience and hearsay to help guide their decisions.
As part of the forage research program at the North Florida Research and Education Center, researchers are investigating uncommon planting dates to fill the forage gaps that normally occur from October to December and from April to June in North Florida. In order to help fill these gaps, they are testing a strategy of late-planted cool-season forages (January and February planting) to fill the traditional April-June forage gap. They are also conducting trials to fill the other gap, October-December, with early plantings in late August or early September. This information is also relevant for producers hit by the atypical weather (drought) like this Fall.
Researchers planted a variety of cool-season grasses, including annual ryegrass (Earlyplod), cereal rye (FL401), oats (Cosaque, Legend 567, and Horizon 201), triticale (Trical 342), and black oats (Soil Saver). These grasses were planted on two dates: January 19 and February 18, 2016. Seeding rates used were: Oats-100 lbs./a, Triticale-85 lbs./a, cereal rye-65 lbs./a, black oats-60 lbs./a, and annual ryegrass-18 lbs./a. Differing seed rates were calculated from seed size and desired plant population. Harvests occurred in April (4/18/2016; Figure 1) and May (5/23/2016).
Figure 1. Harvest of late-planted (January and February) cool-season forages;
first harvest occurred April 18, 2016; UF/IFAS NFREC, Marianna, FL.
As expected, planting in January was better than planting in February for all forages. In general, earlier late plantings should yield better. In the first harvest (April 18, 2016), small grain cultivars (FL401 rye, Legend 567 oats, Soil Saver black oats, and Trical 342 triticale) produced more biomass than annual ryegrass. Cosaque and Horizon 201 oats had severe yield declines because of rust infection. The February planting resulted in lower production, due to the shorter growing season and increased rust infection. The best forage options for a January planting were FL401 rye, Legend 567 oats, Soil Saver black oats, and Trical 342 triticale (Figure 2).
Figure 2. Dry matter yield of cool-season grasses planted in January or February 2016 in North Florida (UF/IFAS NFREC, Marianna, FL). Data from first harvest (4/18/2016).
In the second harvest (May 23, 2016), forages produced less biomass compared to the first harvest, except for annual ryegrass which produced more (Figure 3). This is typically expected for annual ryegrass, which is later maturing and benefits from longer days. Other cultivars were either severely attacked by rust (Cosaque, Horizon 201), were early maturing (FL 401, Legend 567), or were suffering from high May temperatures. One exception is the black oat variety Soil Saver, which outperformed the other tested small grains by the second harvest. Black oats (Avena strigosa) tend to have good heat tolerance.
Figure 3. Dry matter yield of cool-season grasses planted in January or February 2016 in North Florida (UF/IFAS NFREC, Marianna, FL). Data from second harvest (5/23/2016).
Total biomass yield (sum of two harvests) of late-planted cool-season forages are summarized in Figure 4. The January planting resulted in greater yields than the February planting, for all cultivars. Yield reduction was more pronounced for Cosaque and Horizon 201 oats, mostly because of a severe rust attack on the February planting. Small grains, in general, produced more biomass than annual ryegrass, once they reach heading. Later maturing cultivars were not tested, nor a blend of small grains and ryegrass plants in the same plot. That might be a good strategy for maximizing yields. Forage samples are still being evaluated for nutritive value, which might indicate differences in digestibility among the cultivars.
Figure 4. Dry matter yield of cool-season grasses planted in January or February 2016 in North Florida (UF/IFAS NFREC, Marianna, FL). Data from two harvests (April and May).
Take Home Message
The ideal time to plant cool-season grasses in North Florida this year has come and gone. Based on the preliminary results, from only the first year of this trial, it is possible to plant these forages later in the season and still produce a ton of feed /acre; however, forage production will be reduced, mainly because of the shorter growing season. There is also a risk of an early hard freeze, but even so, good-quality forage can still be produced this year. Livestock producers need to take into consideration the planting costs and the benefit they get with cool-season forages and compare with other options, such as purchasing hay and feed. Although annual ryegrass had a lower seed cost, it was not as productive as the small grains last year. Black oats require a lower seed rate than regular oats, and might be a good option since the cultivar tested in this trial was ranked among the top cultivars. If planting regular oats, Legend 567 should be considered because of its rust resistance, while older oat varieties might succumb. Cereal rye is also an option, but forage nutritive value will likely be lower, compared to other options. Although it was not part of this trial, annual ryegrass mixed with other small grains might provide greater seasonal forage yield, with earlier season small grains yields shifting to later season ryegrass yields.
Figure 1. Cool-season grazing in North Florida. Photo credit: Jose Dubeux
Jose Dubeux – University of Florida – NFREC Forage Management Specialist
Have you booked your seeds for cool-season pastures?
Fall is rapidly approaching, so it is time to book your cool-season forage seeds. Cool-season forages represent a great opportunity to improve livestock gain with reduced cost. Whether you are raising stocker cattle or developing heifers to replace your mature cows, it is possible to stock 1.5 to 2 head per acre and get 2 lbs./head/day gain over the 100-120 day period just on cool-season forages. Cool-season forages are also a great option for first-calf heifers, or to improve nutrition for mature cows after calving, resulting in greater reproduction efficiency of the herd. Because North Florida is one of the best places in the country to grow cool-season forages, you cannot miss this opportunity (Figure 1). Mild winter temperature increases the grazing season during this period in North Florida, resulting in greater pasture productivity compared to other regions with harder winters.
In North Florida, the recommended planting dates for cool-season forages range from October 15 through November 15, which is only two months away. If you are overseeding on dormant warm-season grasses, such as bahiagrass or bermudagrass, you need to wait for the first frost before no-till planting into permanent pastures. If you are planting on a prepared seedbed, you can plant earlier. Seed depth, seed rates, and fertilization are important details that require close attention (see Cool-season forage recommendations for specific information on different forage varieties). Attention to detail during the establishment phase can affect the ultimate productivity of annual pastures.
There are numerous forage options for producers, but mixtures of small grains, annual ryegrass, and clovers rank among the top choices (Figure 2). Cool-season forage recommendations are based on variety trials performed in several locations. For this region the best small grain options are Rye, Triticale, and Oats. There are early and late varieties that can be blended to boost the number of overall grazing days, depending on the specificity of your system. Locally bred forages are often better than varieties developed in other regions, because of day length adaptation and disease resistance. Legend 567, for example, is a rust resistant oat released recently by UF/IFAS. Annual ryegrass stretches the grazing season by complementing the small-grain growth curve, therefore, it is wise to plant mixtures of these grasses. Earlyploid, Prine, and Jumbo are examples of annual ryegrass varieties well adapted to Florida. Mixing early and late varieties also works with clovers. If you mix earlier clovers, such as Crimson, with mid- to late-clovers such as ball clover and red clover, you can also extend the clover grazing season. Whenever you are mixing seeds, remember to use a reduced seeding rate as compared to monocultures. At UF/IFAS-NFREC in Marianna, we used a clover mixture with 15 lbs. of Crimson, 6 lbs. of Southern Belle red clover, and 3 lbs. of Ball clover last Fall and it worked well (Figure 2). When you mix forages with different rooting depths and timing of growth, pasture productivity increases because of more efficient utilization of both water and nutrients. Moreover, clovers can add nitrogen (N) to the system via biological N2-fixation, so they require less nitrogen fertilization.
Figure 2. Cool-season mixture (FL401 Rye, RAM Oat, Crimson, Red, and Ball clover) at UF/IFAS-NFREC in Marianna. April, 2016. Photo credit: Jose Dubeux
In grazing systems, producing forage is just one step in the process. In order to be productive, you must also manage the grazing animals to efficiently utilize annual pastures. In grazing trials conducted at the UF/IFAS-NFREC Marianna Beef Unit, on cool-season forages, the average stocking rate along the season was 1.5 to 2.0 steers per acre (600-lbs. steers). Stocking rates should be adjusted as the forage growth rate varies through the season. Grazing animals must also be efficient in the conversion of forage into animal products. The genetics and health care of the animals are crucial to maximize gains and get the most out of your cool-season grazing. If you haven’t booked your cool-season seeds yet, contact your local county extension agent, who can help you determine the best forage options for your farm.